The Collaborative International Dictionary of English v.0.48:

Topsy-turvy \Top"sy-tur"vy\, adv. [Earlier topside-turvey,
   topsy-tervy; probably for top so turvy; that is, the top as
   turvy, as it were turvy; where turvy probably means,
   overturned, fr. AS. torfian to throw.]
   In an inverted posture; with the top or head downward; upside
   down; as, to turn a carriage topsy-turvy.
   [1913 Webster]

WordNet (r) 3.0 (2006):

topsy-turvy
    adv 1: in a disordered manner; "they were piled up higgledy-
           piggledy" [syn: higgledy-piggledy, topsy-turvy]
    2: in disorderly haste; "we ran head over heels toward the
       shelter" [syn: head over heels, heels over head, topsy-
       turvy, topsy-turvily, in great confusion]
    adj 1: in utter disorder; "a disorderly pile of clothes" [syn:
           disorderly, higgledy-piggledy, hugger-mugger,
           jumbled, topsy-turvy]

Moby Thesaurus II by Grady Ward, 1.0:

19 Moby Thesaurus words for "topsy-turvy":
   backwards, chaotic, confused, disordered, disorderly, disorganized,
   every which way, head over heels, higgledy-piggledy, in a muddle,
   inverted, jumbled, messy, mixed-up, muddled, reversed, untidy,
   upside down, vice versa